Equipment Operation A: Gas Analyzers

Question 1

What’s the carrier gas in gas chromatography?

Answer 1

Helium

Question 2

If you’re using gas chromatography to detect helium, then what do you use as the carrier gas?

Answer 2

Use Neon

Question 3

If you’re troubleshooting your gas chromatography machine, you should look for ___ and ___ because they will disrupt gas chromatography.

Answer 3

Water and CO2

Question 4

How does gas chromatography work? Gases pass through a ___ where differing sizes of molecules for the individual gases make each gas exit at different rates.

Answer 4

Separator column

Question 5

What gasses are measured with gas chromatograph?

Answer 5

Ne, O2, N2, CO.

Question 6

What are the advantages of gas chromatography? (x3)

Answer 6

Very accurate and can analyze many gases at once.

Also you only need a small amount of gas.

Question 7

What are the disadvantages of gas chromatography? (x1)

Answer 7

Takes a long time to do.

Question 8

In mass spectrometry, a sample gas is drawn by ___ into an ___. The individual gases are ___ and analyzed to measure ___.

Answer 8

Vacuum
Ionization chamber
Seperated
Gas percentage

Question 9

What are the advantages of mass spectrometry?

Answer 9

Fast. Can be done breath to breath. Can measure multiple gases at the same time.

Question 10

What are the disadvantages of mass spectrometry?

Answer 10

Very expensive, large in size, and requires a lot of maintenance.

Question 11

What gases are measured in mass spectrometry?

Answer 11

Helium, N2, O2, CO2.

Question 12

What gas is N2?

Answer 12

Nitrogen

Question 13

On the test, they give you a bunch of gases and percentages. First thing you want to do is __.

Answer 13

Add them up.
If they don’t add up to 100%, there’s an error.
If they add up to almost 100%, then adjust the gain.
If they add up to over 100%, then reduce the gain.

Question 14

What does an infrared absorption analyzer measure?

Answer 14

Carbon dioxide, carbon monoxide, and methane.

Question 15

A chopper motor and a chopper blade are parts of a ___.

Answer 15

Infrared Absorption Analyzer

Question 16

How do you calibrate an infrared absorption analyzer?

Answer 16

First calibrate low end. Use room air.
Then calibrate high end, use 0.3% of carbon monoxide or carbon dioxide.
Then do low end calibration again.

Question 17

What happens if you have a long sampleing line on any type of analyzer?

Answer 17

Readings will be delayed.

Question 18

What does a thermal conductivity analyzer detect?

It’s also known as ___.

Answer 18

Helium

Wheatstone Bridge Analyzer.

Question 19

Keep thermal conductivity analyzers away from ___ gases.

Answer 19

Combustable gases. (Helium doesn’t burn.)

Question 20

Thermal conductivity analyzers should be calibrated to ___.
Then calibrate with ___.
Then re-zero with ___.

Answer 20

Room air
10% helium
Room air.

Question 21

What does a Geissler Tube Ionizer detect?

Answer 21

Nitrogen (N2)

Question 22

To calibrate a geissler tube ionizer, use __.
Then use ___
Then use ___ to re-zero it.

Answer 22

100% O2 (Can’t use room air because it has N2 in it.)
Then use a different amount of O2 for the high end (amount varies)
Then 100% O2 to re-zero.

Question 23

If there’s erratic readings, or “spikes” on the Geissler Tube Ionizer, what’s that caused by?

Answer 23

Moisture

Question 24

If the Geissler Tube Ionizer isn’t working, it might be a problem with the ___ or the ___.

Answer 24

Pump or the seals might not be tight.

Question 25

How does a gas analyzer work? It has a ____. It’s specialized dirt. What it does is the gas passes through the dirt and each gas passes through at its own speed. Since we know what gas comes out first second third and fourth, we can know what gasses they are. You need a ___.

Answer 25

It has a separator column.

You need a carrier gas.

Question 26

What is another name for gas chromatography analyzer?

Answer 26

Absorption type analyzer.

Question 27

What is another name for an absorption type analyzer?

Answer 27

Gas chromatography.

Question 28

List two things that will mess up gas analyzers and should be checked for when troubleshooting.

Answer 28

Long sampling lines and moisture